7-121 SECTION 752 – TRAFFIC SIGNALS
752.01 PEDESTAL POSTS AND BASES . Steel posts shall use cast iron bases and aluminum posts shall
use cast aluminum bases .
a.Pedestal Posts . Pedestal posts shall have no taper and shall be threaded at the lower end to fit the base.
1.Steel Posts . Steel posts shall consist of 4 -1/2 inch outside diameter galvanized steel pipe conforming to the dimensional requirements of ASTM A501 or ASTM A53 , Type S, Grade B standard weight. Galvanizing sha ll be in accordance with AASHTO M 111 .
2.Aluminum Posts . Aluminum posts shall consist of 4 -1/2 inch outside diameter aluminum structural pipe conforming to the requirements of ASTM B429 , Alloy 6063 -T6.
b.Bases .
1.Cast Iron Bases . Cast iron bases sh all conform to the requirements of AASHTO M 105 , Class 20 or higher. Galvanized cast iron bases shall conform to the requirements of ASTM A126 , Class A. Galvanizing shall be in accordance with AASHTO M 111 .
2.Cast Aluminum Bases . Cast aluminum bases sha ll conform to the requirements of ASTM B26 or ASTM B108 , Alloy SG70A -T6.
752.02 Traffic Signal Assembly .
a.Steel Poles and Baseplates . Steel poles shall consist of tapered tubular shafts. Tapered t ubular shafts for cantilevered overhead signal structures shall meet the applicable requirements of ASTM A595 , Grade A; ASTM A1011 , Grade 50; or ASTM A572 . Tapered t ubular shafts for non - cantilevered overhead signal structures shall meet the applicable requirements of ASTM A500 , Grade B or API 5L , Grade X42. Steel properties shall conform to the requirements of the AASHTO Standard Specifications for Structural Suppor ts for Highway Signs, Luminaires, and Traffic Signals . After fabrication , the shafts shall have a minimum yield strength of 48 ksi. The metal thickness shall be not less than 0.25 inches. The steel poles shall be capable of withstanding the stringing tensi on of the span wire with its signal load without exceeding a deflection of 6 inches and a bending stress limit of 66% of the yield strength. 7-122 The tapered shafts shall be formed, welded, and longitudinally cold -rolled under sufficient pressure to flatt en the weld and form a smooth, tapered tube. A reinforced handhole at least 4 inches in width and 6 inches in height, complete with cover, shall be provided in the pole approximately 18 inches above the base and located at 90° to the span wire on the sid e away from approaching traffic. Stainless steel machine screws shall be provided for attaching the handhole cover. A steel cap shall be provided for the top of each pole with provision for an overhead wire entrance when needed. Stainless steel machine s crews shall be provided for securely fastening the cap to the top of the pole. A 2 inch blind half -coupling shall be welded through the side of the pole 6 inches to 12 inches below the span wire attachment height. A grounding nut shall be located inside the pole easily accessible from the handhole. The baseplate shall consist of a steel plate conforming to the requirements of ASTM A36 . The baseplate shall be attached to the shaft by two continuous welds, one inside and one outside the base. The design sh all be such that the welded connection shall develop the full strength of the adjacent shaft section. An eight -anchor bolt pattern shall be used, unless otherwise shown on the Plans. After fabrication, the shaft and baseplates shall be galvanized in accor dance with AASHTO M 111 and shall have a flat black powder coat finish applied in accordance with Subsection 708.02 unless otherwise specified on the Plans.
b.Cantilever Mast Arms . Material for the mast arms shall conform to the requirements of Subsectio n 752.02(a) . Mast arms shall be fabricated as tapered tubes with a minimum metal thickness of 0.1793 inches (7 -gauge). A flange plate shall be welded to the end for attaching to the vertical pole. A removable cap shall be securely attached to the end. Wire outlets with rubber grommets shall be provided for each indicated signal location.
752.03 TRAFFIC SIGNAL HEADS . Traffic signal heads shall be self -contained assemblies that are
modular and adjustable. The signal heads may contain one or more signal faces as shown on the Plans. Each traffic signal face shall consist of a specific number of signal sections rigidly fashioned together in such a manner as to be watertight and dustproof. 7-123 The components of the signal head shall be polycarbonate with a smooth outer surface and shall be capable of holding the optical units securely in place. The housings, doors, visors, optical units (lenses, reflectors, lamp sockets, and lamps), wiring, tru nnions, and brackets of the signal head shall conform to the performance specifications of the Equipment and Material Standards of the Institute of Transportation Engineers for vehicle traffic control signal heads as well as the following additional requir ements:
a.Housing . The housing of each section shall be a one -piece polycarbonate resin material with front, sides, top, and bottom integrally molded. Two sets of internal bosses shall be provided in each section for mounting terminal strip facilities. The terminal bosses shall have threaded inserts sonically welded into each boss. Signal housings shall be flat black unless otherwise specified in the Plans.
b.Housing Door . The housing door of each signal section shall be of the same material and color as the housing.
c.Optical System . The optical system shall be an LED with a polycarbonate lens (red, yellow, or green) having a nominal diameter of 12 inches unless otherwise specified on the Plans. The optical system shall include dimming capabilities and shall comply with the applicable ITE signal supplement or signal module. The manufacturer’s name, trademark, serial number, and other necessary identification shall be permanently marked on the back of the module.
d.Wiring . Terminal blocks shall be located behind the red LED unless otherwise specified, and shall be a five -position, ten -terminal, barrier -type strip with the terminal designations clearly marked R - A-G-RC-AC. The terminal blocks shall be secured on both ends.
e.Visors . Each signal door shall be equipped with a tunnel polycarbonate visor securely fastened at four points to the door. Visors shall be colored flat black unless otherwise specified on the Plans.
f.Backplates . All backplates shall be louvered and be colored flat black w ith a 2 inch high -visibility yellow retroreflective tape border meeting the requirements of Subsection 750.0 4.
g.Mounting Brackets . The traffic signal head mounting brackets shall be aluminum, enclose all wiring internally, be capable of 360° rotation, and be designed to facilitate the mounting of any size signal to any size mast arm or pole. 7-124 752.04 TRAFFIC SIGNAL CONTROLLERS AND CABINETS .
a.General Requirements . The manufacturer or distributor shall have bench testing performed by an independent testing company which shall certify that such tests have been made and that the traffic signal controller functions properly. Copies of all test results and descriptions of all changes and repairs shall be submitted with the certification. A co py of the controller settings used for the test shall be included in the bench test results. These settings shall be retained in the controller through shipment and installation. Traffic signal equipment design and performance shall meet or exceed all requ irements of the NEMA standards for traffic control systems. Operation of the equipment shall be consistent with the MUTCD . The controller along with all auxiliary equipment shall be capable of producing the timing plans and coordination shown on the Plans.
b.Controller . All traffic signal controllers shall meet the requirements of NEMA TS 2 , Type 2, be actuated, solid -state, menu -driven, with keyboard entry, and be compliant with ATC 5201 v06A . They shall have a minimum of 16 phases with dual maximum capa bilities, and an internal time - based coordinator capable of providing at least four cycle lengths with multiple programs per cycle. All controllers shall have all necessary hardware and software for ethernet communications. All controllers shall be connect ed vehicle compatible. All controllers shall have a minimum of two USB ports. Controllers shall have remote communications capability unless otherwise specified on the Plans. Each installation shall include the following:
1.Malfunction Management Unit . A 16 channel malfunction management unit (MMU) with stop-timing function, liquid crystal display, and sufficient recording storage capacity for at least nine events. The MMU and the controller shall be wired to ensure that the events logge d by MMU and the controller indications at the time of failure can be uploaded directly to a computer. The MMU shall be flashing yellow arrow compatible and IP addressable.
2.Switches and Relays . Sufficient load switches and flash transfer relays for al l 16 phases.
3.Load Switches . LED -display load switches on the input side and labeled on the cabinet wall.
4.Remote Flasher . Remote flasher shall be included. 7-125 (c) Cabinet . The controller and all auxiliary equipment shall be enclosed within a pre -wired, rainproof P44 controller cabinet meeting the requirements of ANSI/NEMA 250 , Type 3R. Unless otherwise specified on the Plans, the cabinet shall have a flat black finish and be mounted on a 15 inch base extension. The cabinet shall be sized to provid e ample space for housing all equipment necessary to provide the timings shown on the Plans. Each cabinet shall have a weatherproof plastic envelope of sufficient size, at least 18 inches × 24 inches, to store wiring diagrams, program manuals, and other do cuments. The cabinet shall have a main door within which a police door (auxiliary door) shall be placed. The police door shall house a compartment with switches for Flash -Automatic; Power, On -Off; and Signal, On -Off. A metal plaque listing ownership and e mergency telephone numbers shall be attached to the outside of the cabinet. The design and configuration of the plaque shall be as shown on the Plans. The cabinet shall include an external generator plug and transfer switch capable of running the signal s ystem off a standard portable generator which can be connected to the cabinet without opening the cabinet doors. The transfer switch shall toggle the cabinet between AC line service and generator supplied power. The cabinet shall contain two suitably desi gned vent fans and thermostat with a range of 120°F to 160°F. The thermostat shall be initially set to 120°F. The controller cabinet shall contain a strong mounting table, sliding track, and a hinged, adjustable fixed or folding support of such constructi on that it will permit the controller or other equipment to be withdrawn from the cabinet for inspection or maintenance without breaking any electrical connections or interrupting normal operation of the controller. An LED lamp capable of illuminating all areas of the cabinet, two convenience outlets, ground fault interruption protection, and surge protection shall be provided. Six non -ground fault outlets for equipment power shall be provided on the left side of the cabinet to be fed from the load side of the main breaker. A wiring panel shall be included in each cabinet mounted in such a way as to provide visibility and accessibility. The lowest row of terminals shall be at least 3 inches from the bottom of the cabinet. The main door lock of the cabinet shall be a No. 2 tumbler -type lock as recommended by the manufacturer of the equipment. Two keys shall be furnished for the lock. A different style of lock that is appropriate for the application shall be provided for the police door. 7-126 (1) Spare Equip ment . In addition to equipment furnished to provide a functional signal system, the Contractor shall supply the following spare parts in each cabinet:
a.One flasher unit (independent of the controller).
b.One transfer relay.
c.One flash drive, USB 2.0 or later, containing controller data.
d.One cabinet lamp LED.
e.One filter for the ventilation system.
f.One flash transfer relay.
g.One bus interface unit (BIU) in a protected container.
h.Six additional load switches.
2.Relays . Relays shall not be used in connection with any automatic non -flashing red, yellow, or green indications without the approval of the Engineer. All relays shall be jack -mounted.
3.Snap Switch . Each controller shall be equipped with a snap switc h that will disconnect the timing mechanism and signal lights from all outside sources of electrical power.
4.Lightning Arrester . Each controller shall be equipped with a suitable effective lightning arrester that filters lightning or high voltages to gr ound, protecting the internal components of the controller.
5.Flasher . Each controller shall be equipped with a flashing mechanism capable of providing flashing operation at a rate of not less than 50 or more than 60 flashes per minute, part of which may be yellow and part red, or all red, as directed by the Engineer. The illuminated period of each flash shall not be less than 50% nor more than 67% of the total cycle. Flashing mechanisms shall be in an encapsulated cube style configuration, shall be adeq uately housed and protected from the weather, and shall be of such design as to be accessible for inspection, cleaning, and adjustment without disconnecting any part. The flasher shall be capable of flashing two inductive or tungsten loads and shall operat e within a line voltage range of 95 volts AC to 135 volts AC. The flashing operation shall begin automatically if the controller malfunctions and when called for by the timing plan. In addition, flashing shall be capable of being manually controlled by a s witch in the police door. The controller itself need not be present to operate the signals in flashing mode. 7-127 752.05 AERIAL FLASHING BEACONS . The applicable portions of Subsection 752.04 shall apply in addition to the following specific functional requirements :
a.Flasher . The controller shall be equipped with a flashing mechanism which meets the requirements of Subsection 752.04(c)(5) .
b.Cabinets . The complete flashing mechanism and related interference filters shall be enclosed withi n a rainproof, cast aluminum cabinet meeting the requirements of ANSI/NEMA 250 , Type 3R. The cabinet shall be sized to provide ample space for housing the flashing mechanism, filters, and fuse panel. The cabinet shall have a main door and lock. The lock shall be a No. 2 tumbler -type lock as recommended by the manufacturer of the equipment. Two keys shall be furnished for the lock. The cabinet shall contain a suitably designed vent.
c.Aerial Flashi ng Beacon Signal Heads . Flashing beacon signal heads shall be self -contained assemblies that are expandable, adjustable, and may contain one or more signal faces as shown on the Plans. The housings, doors, visors, optical units (lenses, reflectors, lamp sockets, and lamps), wiring, trunnions, and brackets comprising the signal head shall conform to the requirements of the Equipment and Material Standards of the Institute of Transportation Engineers and the applicable portions of Subsection 752.03 unless o therwise specified.
752.06 ELECTRICAL CONDUIT . Electrical conduit shall conform to the following requirements:
a.Rigid Polyvinyl Chloride (PVC) Electrical Conduit . Rigid PVC electrical conduit shall be schedule 80 and shall meet or exceed the requirem ents of ASTM D1784.
b.High -Density Polyethylene (HDPE) Electrical Conduit . High -density polyethylene (HDPE) electrical conduit shall be schedule 80 and shall meet or exceed the requirements of ASTM D3350.
c.PVC Coated Rigid Metal Conduit (RMC) .
1.Conduit . Conduit shall be galvanized steel RMC in accordance with UL 6 and ANSI C80.1 . RMC shall have an external 40 mil PVC coating and a 2 mil internal urethane coating in accordance with NEMA RN 1 . The PVC coating shall be verified for adhesion perf ormance in accordance with ETL PVC -001. 7-128 (2) Elbows, Nipples, and Couplings . Elbows, nipples, and couplings shall be galvanized steel RMC in accordance with UL 6 and ANSI C80.1 . Elbows, nipples, and couplings shall have an external 40 mil PVC coating and a 2 mil internal urethane coating in accordance with NEMA RN 1.
3.Fittings . Fittings shall be in accordance with UL 514B .
752.07 Traffic Signal Conductor Cable .
a.Polyethylene -Insulated, Polyvinyl Chloride (PVC) Jacketed Signal Cable . Polyethylene -insulated, PVC -jacketed signal cable shall conform to the requirements of IMSA 19 -1.
b.Polyethylene -Insulated, Polyethylene -Jacketed Communication Cable . Polyethylene -insulated, polyethylene jacketed communication cable shall conform to t he requirements of IMSA 20 -1.
c.Polyethylene -Insulated, Polyvinyl Chloride (PVC) Jacketed, Integral Messenger Signal Cable . Polyethylene -insulated, PVC jacketed signal cable with integral supporting span wire for aerial installation shall conform to the requirements of IMSA 19 -3.
d.Polyethylene -Insulated, Polyethylene -Jacketed, Integral Messenger Communication Cable . Polyet hylene -insulated, polyethylene -jacketed communication cable with integral supporting span wire for aerial installation shall conform to the requirements of IMSA 20 -3.
752.08 VEHICLE DETECTORS . Vehicle detectors used for actuating traffic signal controlle rs shall use
radar presence detection or the method shown on the Plans. The vehicle detectors shall have at least a 90° field of view and a detection range of 140 feet. The vehicle detectors shall be capable of detecting in real -time the presence of both stopped and moving vehicles and bicyclists. The vehicle detectors shall be remotely accessible to allow for traffic monitoring and sensor management. The configurations and installation of the vehicle detectors shall be in accordance with the manufacturer ’s recommendations. The vehicle detectors shall be located at locations per the manufacturer’s recommendations.
752.09 Junction Boxes and Pull Boxes .
a.Junction Boxes
1.Material . Junction boxes shall be constructed of precast monolithic polymer co ncrete.
2.Cover Gasket . A sufficient cover gasket shall be provided to reduce the inflow of fluids. 7-129 (3) Junction Box Covers . Junction box covers shall be flush with the boxes and frames. All junction box covers shall be skid resistant. Junction box c overs shall have a logo punched, formed, or stamped into a flat rectangular area. The minimum letter height shall be 1/2 inch and the minimum depth shall be 1/16 inch. The logo on the covers shall read “TRAFFIC SIGNAL” unless otherwise noted on the plans.
4.Interior Dimensions . Junction boxes shall be a minimum of 21 -1/4 inches long, 11 -3/4 inches tall, and 12 inches deep.
5.Enclosure Integrity . Junction boxes shall meet the requirements of ANSI/SCTE 77 , Tier 22 for underground enclosure integrity.
b.Pull Boxes
1.Material . Pull boxes shall be constructed of Concrete, Class B.
2.Cover Gasket . A sufficient cover gasket shall be provided to reduce the inflow of fluids.
3.Pull Box Covers . Pull box covers shall be flush with the boxes and frames. All pull box covers shall be skid resistant. Pull box covers shall have a logo punched, formed, or stamped into a flat rectangular area. The minimum letter height shall be 1/2 inch and the minimum depth shall be 1/16 inch. The logo on the covers shall read “TRAFFIC SIGNAL” unless otherwise noted on the Plans.
4.Interior Dimensions . Single pull boxes shall be a minimum of 16 inches long and 16 inches wide. Double pull boxes shall be a minimum of 16 inches long and 38 inches wide. The depth for both single and double pull boxes will depend on installatio n location and depth needed for conduit.
5.Enclosure Integrity . Pull boxes shall meet the requirements of ANSI/SCTE77 , Tier 22 for underground enclosure integrity.
752.10 ACCESSIBLE PEDESTRIAN SIGNALS . Accessible pedestrian signals (APS) shall be in
accordance with the MUTCD .
a.Pedestrian Pushbutton Assemblies . Pedestrian pushbutton assemblies shall meet all Americans with Disabilities Act requirements. The plunger head shall have a minimum diameter of 2 inches and the force required to operate the plu nger shall not exceed 5 pounds. The pushbutton shall activate both the walk interval and the APS. 7-130 (1) Color . The color of the pushbutton shall contrast visually with the housing or mounting.
2.Locator Tone . The pushbutton assembly shall include an inte gral locator tone. The locator tone shall have a duration of 0.15 seconds or less and shall repeat at 1 second intervals. The locator tone shall be 2 dB minimum and 5 dB maximum above ambient noise levels and shall be responsive to ambient noise levels.
3.Tactile Features . The pushbutton assembly shall incorporate a raised arrow. The arrow shall be raised a minimum of 1/32 inch and shall have a minimum length of 1 -1/2 inches. The arrow color shall contrast with the background. The pushbutton shall vibrate to indicate that the walk interval is in effect.
4.Audible Features . The APS shall include an audible indication of the walk interval by either tone or voice and shall be audible from the near side of the associated crosswalk. If the tone for the walk interval is the same as the locator tone of the pushbutton, it shall have a faster repetition rate than the associated locator tone. The audible features shall have automatic volume adjustment based on the ambient noise levels. Audible features shall be no more than 5 dB louder than ambient sound up to a maximum volume of 89 dB measured at 36 inches from the device. When voice messages are used, they shall include a clear message that the walk interval is in effect and shall indicate to which cro ssing it applies. Audible features may be integral to the pedestrian pushbutton assembly or produced through a separate speaker housing.
b.Pedestrian Signal Heads . Pedestrian signal heads shall meet or exceed the requirements of MIL- STD-810F, Method 506. 4, Procedure I.
1.Controller Compatibility . Pedestrian signal heads shall be compatible with traffic signal controllers meeting the requirements of NEMA TS 2 , Type 2.
2.Signal Face Dimensions . The pedestrian signal head face shall be 17.7 inches wide and 16.0 inches tall.
752.11 GROUNDING ELECTRODES . Grounding electrodes shall include grounding rods and
grounding conductors.
a.Grounding Rods . Grounding rods shall be copper -clad steel rods with a diameter of 5/8 inch and a minimum total length of 8 feet, conforming to the requirements of UL 467.
b.Grounding Braid . Grounding braid shall conform to the requirements of UL 467.
c.Grounding Co nductors . Grounding conductors shall be installed throughout the system back to the power source. The earth shall not be used as the sole equipment -grounding conductor. Grounding conductors shall be No. 6 AWG soft copper or stranded copper conductors. 7-131 752.12 PAN -TILT -ZOOM CAMERA . Pan -tilt-zoom cameras shall be suitable for outdoor use.
a.Video Quality . Pan -tilt-zoom cameras shall provide a minimum video resolution of 1080p.
b.Zoom Capability . Pan -tilt-zoom cameras shall be capable of a minimum of 40X optical zoom, 12X digital zoom, and a total of 480X zoom.
c.Pan/Tilt Capability . Pan -tilt-zoom cameras shall be capable of 360° pan and a minimum of 220° tilt.
d.Lens . Pan -tilt-zoom cameras shall have an autofocus, auto -iris lens.
e.Memory . Pan -tilt-zoom cameras shall have a minimum of 1024 MB of RAM and 512 MB of flash memory.
752.13 EMERGENCY VEHICLE PREEMPTION SYSTEM . All components of the emergency vehicle
preemption system shall be new equipment produced by the same manufacturer.
a.Signal detection range . The emergency vehicle preemption system’s receiver shall have a minimum detection range of 2,500 feet.
b.Field of view . The emergency vehicle preemption system’s receiver shall have a minimum field of view of 13°.
c.Weather resistanc e. The emergency vehicle preemption system receiver’s enclosure shall be suitable for all -weather use and have a weep hole allowing for moisture to escape.
752.14 POWER DROP STANCHION . Power drop stanchions shall comply with the National Electrical
Code , the requirements of the utility company providing the power source, and the Standard Drawings. 7-132 SECTIO N 753 – HIGHWA Y ILLUMINATION 753.0 1 LIGHT POLE FOUNDATIONS .
a.Concrete . Concrete shall conform to the requirements of Section 541 for Concrete, Class B.
b.Reinforcing Steel . Reinforcing steel for light pole bases shall conform to the requirements of Section 507 for Level I reinforcing steel .
c.Electrical Conduit . Electri cal conduit for light pole bases shall conform to the requirements of Subsection 752.0 6(a).
d.Anchor Bolts . Anchor bolts for light pole bases shall be per the transformer base manufacturer’s recommendation and conform to the requirements of Subsection 71 4.09.
e.Grounding Electrodes . Grounding electrodes for light pole bases shall conform to the requirements of Subsection 752.1 1. 753.0 2 TRANSFORME R BASES .
a.Transformer Bases . Transformer bases and transformer base doors shall consist of a one -piece aluminum casting conforming to the requirements of ASTM B26 or ASTM B108, Alloy SG70A - T6, 356 -T6. Galvanized bolts, nuts, washers, and other hardware shall be provided to attach th e transformer base to the anchor base of the light pole. Galvanizing for bolts, nuts, washers, and other hardware shall conform to the requirements of Subsection 726.0 6.
b.Mounting Hardware . Hardware for mounting the transformer base door to the transfor mer base shall be stainless steel. 753.0 3 LIGHT POLES .
a.Anchor Bases . Anchor bases shall consist of a one -piece aluminum casting conforming to the requirements of ASTM B26 or ASTM B108, Alloy SG70A -T6, 356 -T6.
b.Pole Shafts . Pole shafts shall be fabricated from tapered one -piece seamless aluminum tubes conforming to the requirements of ASTM B221, Alloy 6063 -T6, Alloy 6061 -T6, or Alloy 6005 - T5. The minimum wall thickness shall be 0.125 inch for mounting heights of less than 20 feet and 0.188 inch for mounting heights of 20 feet or more.
c.Pole Caps . Pole caps shall consi st of a one -piece aluminum casting conforming to the requirements of ASTM B26 or ASTM B108 , Alloy SG70A -T6, 356 -T6.
Source: Vermont Standard Specifications for Construction, 2024 Edition. Pages 1273–1283 of 1,380.